The Recovery Needle May Move In The Wrong Direction

Recovery may take longer when surgery is required to remove bruised tissue and relieve pressure or a major blood clot on the brain after a traumatic brain injury. Even when such a procedure succeeds, improvement still can take several weeks. The recovery needle may move in the wrong direction if the patient displays ominous signs, such as pupils that don’t respond to light or spasms in the arms and legs. While many comatose patients recover, we know from the very start in others, the outcome is likely to be poor. A major determinant is sustained, increased intracranial pressure. This typically happens in individuals with trauma to the brainstem and loss of many brainstem reflexes. Whether aggressive, early treatment affects outcome in such cases is unknown. I’ve rarely seen any of these patients make a perfectly good recovery. Most of them end up in nursing homes and don’t make enough progress to qualify for admission to a rehabilitation center. When examination and test results are consistently poor, we often conclude that rescue surgery isn’t an option. Most individuals older than age 80 can’t tolerate trauma to the brain well, and a freak fall may completely change the outlook, even if they previously functioned at a high level. Poor outcomes after traumatic brain injury are expected in older individuals in a sustained coma, as well as in younger individuals who have lost many brainstem reflexes.

Day After Day

Blood flow can also be impaired due to hemorrhagic stroke, which causes bleeding into the brain. An ischemic stroke cuts off blood flow, whereas a hemorrhagic stroke allows too much blood into the brain. Acute ischemic or even hemorrhagic stroke doesn’t always cause loss of consciousness. After a stroke, individuals often are alert, although many don’t fully realize what has happened to them. Most acute strokes occur in small arteries or involve a part of the brain that barely affects structures governing alertness and awareness. Declining responsiveness in an individual who’s had a stroke may have another cause, such as the effects of sedative drugs administered during transport, a laboratory abnormality such as a rapid spike in blood sugar, or a seizure. Coma after a stroke usually, but not always, indicates large areas of destruction, such as a great deal of bleeding in the brain. A stroke in the brainstem due to a clot in the basilar artery is another common cause of initially unexplained coma. Even a small area of damage in the brainstem may interrupt arousal mechanisms. Conventional wisdom once was that bleeding in the brain would resolve quickly, but we now know that bleeding can continue and have a snowball effect. Prognosis in an individual with a deteriorating hemorrhagic stroke generally depends on whether it is possible to remove the clot causing the bleeding and how soon surgery can take place. Location of the clot is another factor.

My Soul's Got Wings

Many clots lodge deep in the brain and can only be reached by cutting into healthy surrounding tissue, which neurosurgeons are very reluctant to do. Moreover, clinical trials have shown that the outcome may be worse when deep clots are removed. Other therapies, such as using a catheter to suck out the clot, have been tried, but often the clot returns. Clotting medications may stop bleeding in the brain, but they may cause clots in other arteries, creating a worse problem. Bleeding in the brainstem and in the cerebellum in the back of the head is much less common but very dramatic. Patients may arrive in the emergency room in a deep coma or spiral downward in a matter of hours. However, the outcome can be quite good if the cause is blood in the cerebellum that’s pressing on the brainstem and the blood clot can be removed. That’s why these patients need to be seen by a neurosurgeon right away. The effects of a coma from ischemic stroke are similar. The outcome often is poor in this case. There’s a risk, however, that the artery may not open during the procedure. If that happens, the patient won’t recover function.

Coming In From The Cold

Predicting outcome in an individual with a ruptured aneurysm is complex and difficult. If a drain is placed or the clot is removed from the brain soon after the rupture, the patient may improve rapidly within hours after the procedure. But if most brainstem reflexes remain lost after such interventions, recovery is rare. Other major factors that point to poorer outcomes are spasm in an artery and an inability to control it effectively with medication. As with other causes of coma, age greatly influences outcome, and in individuals older than age 80, survival that includes meaningful functioning is uncommon. Other therapies also are very helpful. Patients with meningitis or encephalitis who are comatose are obviously in a worse state, but many will improve, often over a matter of weeks and, sometimes, within days. I’ve seen barely responsive patients with meningitis improve dramatically after receiving the right antibiotics. However, if an infection in the arteries leading to the brain or clots in the brain’s venous system cause strokes, a good outcome becomes significantly less likely. Some brain infections, such as rabies encephalitis, are so devastating that there’s no chance of a good outcome. Although rabies is very uncommon in western countries, it has a nearly 100% mortality rate. There’s also no effective treatment for many fungal infections of the brain or for West Nile virus encephalitis, and therefore, outcome is poor. In individuals with suppressed immune systems, these infections can be particularly devastating. Some patients with meningitis recover fully, but more invasive neurologic forms can cause marked changes in many parts of the brain. In general, 20% of patients with West Nile virus encephalitis die, and death is much more likely in older adults. Herpes simplex encephalitis is a common infection that also can cause significant injury to the brain. Most patients do awaken, but they may have markedly impaired memory and speech. In this condition, the immune system attacks the brain or certain parts of it for an unknown reason.